#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
//https://www.luogu.com.cn/problem/CF25B
using namespace std;

const int N = 110;
int a[N];
int n;

int main()
{
	cin >> n;

	for (int i = 1; i <= n; ++i)
	{
		char ch;
		cin >> ch;
		a[i] = ch - '0';
	}

	int cnt = 1;
	int i = 0;
	if (n % 2 == 0)
	{
		for (i = 1; i <= n - 2; ++i)
		{
			cout << a[i];
			if (cnt++ % 2 == 0)
				cout << '-';

		}
	}
	else
	{
		for (i = 1; i <= n - 3; ++i)
		{
			cout << a[i];
			if (cnt++ % 2 == 0)
				cout << '-';
		}
	}

	for (; i <= n; ++i)
	{
		cout << a[i];
	}



	return 0;
}